Abstract

The gradient in soil characteristics from the bulk soil to the root surface is important to roots and to the organisms that live in the rhizosphere. Our ability to measure ion concentrations at the root surface is extremely limited, and models are largely untested. We used data from a well studied Norway spruce stand in SW Sweden to compare the measured difference in nutrient concentrations between rhizosphere and bulk soil with the difference predicted by a steady-state simulation model based on ecosystem budgets of nutrient uptake. The simulation model predicted depletion of NH4, Ca, Mg, K in the rhizosphere, which shows that budgeted uptake rates were greater than the mass flow of bulk solution towards the root. In plots treated with ammonium sulphate, the model predicted an accumulation of S in the rhizosphere. In contrast, the observed rhizosphere concentrations were generally enriched in nutrients, relative to bulk soil. Collecting rhizosphere soil adhering to root surfaces may not be an appropriate method for describing the concentration gradient around the root. In addition, the simulation model omits some processes affecting conditions in the rhizosphere that are important to explaining nutrient uptake

Published in

Plant and Soil
2003, Volume: 257, number: 1, pages: 133-142
Publisher: KLUWER ACADEMIC PUBL

SLU Authors

• Majdi, Hooshang

  • Department of Ecology and Environmental Research, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Publication identifier

DOI: https://doi.org/10.1023/A:1026257508033

Permanent link to this page (URI)

https://res.slu.se/id/publ/937